Editing Thundersnow (section)

===Synoptic forcing===
Synoptic snow storms tend to be large and complex, with many possible factors affecting the development of thundersnow. The best location in a storm to find thundersnow is typically in its [[NorthWest]] [[Quadrant (plane geometry)|quadrant]] (in the [[Northern Hemisphere]], based on observations in the [[Midwestern United States]]), within what is known as the "comma head" of a mature [[extratropical cyclone]].<ref>Patrick S. Market, Angela M. Oravetz, David Gaede, Evan Bookbinder, Rebecca Ebert, and Christopher Melick. [http://ams.confex.com/ams/pdfpapers/72662.pdf Upper Air Constant Pressure Composites of Midwestern Thundersnow Events.] {{Webarchive|url=https://web.archive.org/web/20110609170131/http://ams.confex.com/ams/pdfpapers/72662.pdf |date=2011-06-09 }} Retrieved on 01-11-2006.</ref><ref name="Rauber2014">{{cite journal |title=Stability and Charging Characteristics of the Comma Head region of Continental Winter Cyclones |journal=J. Atmos. Sci. |last=Rauber |first=R.M. |pages=1559–1582 |volume=71 |issue=5 |year=2014 |doi=10.1175/JAS-D-13-0253.1 |bibcode= 2014JAtS...71.1559R|display-authors=etal|doi-access=free }}</ref> Thundersnow can also be located underneath the [[Occluded front|TROWAL]], a trough of warm air aloft which shows up in a [[surface weather analysis]] as an inverted trough extending backward into the cold sector from the main cyclone.<ref>National Weather Service Office, St. Louis, Missouri. [http://www.crh.noaa.gov/lsx/science/pdfppt/thun_prox_soundings.ppt Thundersnow Proximity Soundings.] Retrieved on 01-11-2006. {{webarchive|url=https://web.archive.org/web/20110523213153/http://www.crh.noaa.gov/lsx/science/pdfppt/thun_prox_soundings.ppt |date=2011-05-23 }}</ref> In extreme cases, thunderstorms along the cold front are transported towards the center of the low-pressure system and will have their precipitation change to snow or ice, once the cold front becomes a portion of the occluded front.<ref name="Rauber2014"/> The [[1991 Halloween blizzard]], [[Superstorm of 1993]], and [[White Juan]] are examples of such blizzards featuring thundersnow.